The first waterbeds utilized a simple bag or bladder peripherally bounded by a frame, such as shown in U.S. Pat. No. 3,585,356 to Charles Hall. Such an arrangement made it possible to relieve the plastic bag from the work of confining the water within a boundary. The bag tension could then be reduced to zero, if so desired, so that the weight of a person could be supported primarily by buoyancy. Flotation was achieved. Many users found objectionable the continuing wave movement resulting once the body of water was disturbed. Soon there appeared various forms of baffle structures designed to damp wave motions. Generally these structures included elements welded at opposite ends to the top and bottom layers of the bag. Manufacture has been a problem. Thus the baffles must be welded in place in progressive rows, leaving access to the interior of the bag during the process. Ultimately the outer layers of the bag must be sealed together. Some of the welds, of necessity, will be butt welds which are structurally inferior to lap welds.
The primary object of the present invention is to provide a baffle structure for a waterbed mattress in which the baffles are securely installed in a bag that is entirely lap welded. Another object of the present invention is to provide a means for incorporating baffles in a lap welded waterbed mattress bag made in accordance with my prior U.S. Pat. No. 3,825,172 issued July 23, 1974 and entitled TUBULAR FLEXIBLE BAG WITH LAP WELDED ENDS.